def after_speed_up_time(hour:int,minute:int,beisu:int):
	return (hour * 60 + minute)/beisu

print("请输入视频时长（小时)：")
hour = int(input())
print("请输入视频时长（分钟)：")
minute = int(input())
print("请输入倍速：")
beisu = int(input())

time = after_speed_up_time(hour,minute,beisu)
print("加速后"+ time + "分钟")